As is well known to those skilled in the art, suitable heavier hydrocarbons may be employed as charge stock for various products including lubricating oils, automatic transmission fluids, etc. Commonly, however, it is found that the charge stocks need considerable processing in order to make them suitable as a base oil for such uses. Various processes may be employed to convert these charge oils into base stocks characterized by decreased wax content, decreased pour point, decreased aromatics content, etc.
There is a large body of literature and patents which address this area. Typical of these are the following:
Bijward, H. M. J. et al The Shell Hybrid Process, an Optimized Route for HVI (High Viscosity Index) Lube oil Manufacture paper from Pet. Ref. Conf. of the Jap. Pet. Inst 27-28 Oct. 1986, p16;
Bulls, S. et al Lube oil Manufacture by Severe Hydrotreatment Proc. Tenth World Pet. Congress Vol 4, 1980 p221-8.
______________________________________ U.S. Pat. No. 3,268,439 U.S. Pat. No. 3,658,689 U.S. Pat. No. 3,764,516 U.S. Pat. No. 3,830,723 U.S. Pat. No. 4,547,283 U.S. Pat. No. 4,900,711 U.S. Pat. No. 4,911,821 EUR 0 321 299 EUR 0 321 302 EUR 0 335 583 BRIT 1,098,525 ______________________________________
Continuing studies are in progress in an attempt to improve the quality of base stocks so that they may be employed as premium motor oils, transmission fluids, etc. There is also a need to process sulfur-containing charge to prepare satisfactory product--without hydrotreating. It is also found that there is a need to treat charge stock such as slack wax, typically containing substantial content of sulfur (above 100 ppm) and paraffins in order to permit attainment of product oils (suitable for such desired uses) characterized by high viscosity index (typically 120-150) and reduced or low pour point at mid-range viscosity (typically .ltoreq.300 SUS @100.degree. F.).
It is an object of this invention to provide a process for treating a waxy hydrocarbon such as slack wax to convert it into a product oil containing decreased content of normal paraffins and increased content of isoparaffins. Other objects will be apparent to those skilled in the art.